1. Field of the Invention
This invention relates to energy measuring systems and methods, in particular to systems and methods of measuring thermal energy as may be done in a calorimeter. In some embodiments the thermal energy measuring systems are able to switch between an adiabatic and an isothermal mode of operation.
2. Description of the Prior Art
calorimeters are devices used to measure thermal energy in the form of heat either released or absorbed in the course of a chemical or physical process. Traditionally, calorimeters used in various industries, such as cement and concrete, food, bio sciences, rubber, polymers and heavy chemicals among others, belong to one of two types: isothermal or semi-adiabatic. In isothermal calorimeters, the temperature of the environment in which the sample is placed is maintained at an essentially constant value (e.g. within a fraction of a degree), while the amount of thermal power generated (or absorbed) by the sample is being measured as a function of time. Semi-adiabatic calorimeters use the opposite approach: thermal energy generated or absorbed by the sample is held within the sample, i.e. the heat exchange between the sample and the environment is held at a value close to zero, while the sample temperature is being measured as a function of time.
Both isothermal and semi-adiabatic calorimeters incorporate elements which are found in the vast majority of marketed devices. Isothermal calorimeters use a massive metal block utilized as a heat sink to stabilize the temperature in the environment around the sample. Semi-adiabatic calorimeters use a thick layer of thermal insulation to minimize thermal energy flow. Because of the considerable amount of insulation and other materials used with these calorimeters, they are typically large and bulky systems.